Feeling blue about the white stuff winging our way? Then why not pretend it’s summer by eating outside all winter? Alfresco bars and restaurants let you ignore the plunging mercury via the ingenious use of heaters, retractable roofs and even complimentary Slankets (you know, blankets with sleeves). Hey, sometimes you have to sacrifice a little dignity to stay snug.

Outdoor heaters are fine and good, but there’s nothing like a big ol’ fire pit to make you feel like you’ve escaped from the rat race. Union Pool in Williamsburg offers that ultimate city rarity in its backyard: a 30-inch copper blaze with circular seating for up to 15 people. Thanks to its size, it easily heats up the surrounding area.

“I’m not a country boy, but it makes me feel like I should be a country boy,” says Donitello Russo, a 26-year-old from Bensonhurst.

“It’s nice, man,” agrees his friend Erwin Yusof, 23, also of Bensonhurst. “Where else can you have a freaking fire pit in New York City without getting arrested?”

WINTER FUEL Union Pool’s front room hosts the bar, where drinkers can clock in for happy hour specials such as a $5 ginger julep or $4 well drinks. Through the end of January, bring a can of nonperishable food and exchange it for a can of Budweiser.

The real crowd-pleaser is out back, by the fire, where El Diablo Taco Truck conveniently sits, serving beef, chicken, pork and vegetable tacos for just $3. There’s also chips with guacamole or queso ($5) and grilled corn ($3). On any given night, you’re likely to see Brooklynites crowding around the flames, chowing down.

“It’s funny because it’s become an indicator that you’ve been to Union Pool,” says Sage Geyer, the spot’s managing partner. “Because you smell like smoke.”

Upstairs at the Kimberly has a lot of draws — signature cocktails, striking views of the Chrysler Building and an outdoor fireplace. But the most unique winter feature is the heated floor within the glass-enclosed rooftop space, which automatically turns on when the temperature outside drops to 32 degrees.

“It makes me want to take my shoes off and dance barefoot!” squeals Bushra Zeim, a 28-year-old from Long Island.

Thirty stories up inside the Kimberly Hotel, this Midtown boite is a favorite after-work spot for the local business and fashion crowds. The enclosed bar features plenty of space to relax in, with classy neo-Gothic chairs. There’s also room to kick off your shoes, should the DJ get you going. Hand-painted Venetian walls and a custom-made bronze bar add to the ambience, while an open outside area features lounge seating and a fireplace.

WINTER FUEL Warm up with savory snacks such as truffled mac and cheese ($12) or rich desserts such as chocolate molten lava cake with dulce de leche ice cream ($11). Specialty cocktails include the “Rum Service,” a mix of tobacco-infused rum, honey, pear and lime ($16).

Sometimes nothing feels quite as nice as snuggling up with a blanket on your couch while sipping a hot drink. Southwest Porch takes that tried-and-true pleasure and relocates it outside. During the winter months, the outdoor eatery in Bryant Park offers a rack of red

and blue Slankets for customers’ use — as well as a fire pit large enough for several groups of friends to flock around.

“It’s nice and relaxing to come here and have a drink and enjoy the park,” says Naxime Colange, a 21-year-old from France. He and his friends were uncertain about the Slankets — until they tried them.

“Everyone is afraid of looking like they’re on an infomercial, so that’s one of the hurdles,” laughs Jeffrey Zurofsky, one of Southwest Porch’s founders and partners. “But once someone in the group grabs one, it’s pretty automatic that everyone’s going to use them.”

WINTER FUEL Upping the coziness factor is a roster of hot drinks, from hot chocolate ($3.67) to Irish coffee ($9.19). Pair one with finger foods such as the warm ancho cheddar dip with tortilla chips ($8.27) or popcorn with ancho chili and lime ($3.67) and you’ll be nice and toasty in no time.

Eataly’s rooftop bar and restaurant, Birreria, spends its summers wide open. But colder weather doesn’t mean everything gets locked up. The Alpine Italian bar and restaurant on the 14th floor of the former Toy Building boasts a retractable roof that employees can open or close depending on the weather.

“I love that you’re kind of enclosed, but then you look out, and there’s this gorgeous building next to you,” says customer Alicia Amarant, a 25-year-old from Fort Greene, Brooklyn.

“You feel like you’re on a warm patio,” agrees her friend Caroline Shaw, a 24-year-old from Harlem. “I feel comfy.”

It takes two men using a pulley system to retract the heavy Plexiglas roof. When they’re done, they simply tie it up around a cleat, making it look very much like a sailboat.

Because of the surrounding buildings, the rooftop doesn’t get a lot of wind, allowing the restaurant to keep the roof open frequently. Heat lamps also keep things cooking.

But here, patrons actually hope for stormy weather.

“When it snows, you really feel like you are in a snow globe,” says Nicola Farinetti, one of Eataly’s founders and store managers.

Sitting atop 15 floors on 11th Avenue, the Press Lounge’s rooftop bar offers awe-inspiring views of Times Square, the Hudson and the Upper West Side.

The spectacular spot showcases a glassed-in lounge (full of swanky yet comfortable chaises) and an open outdoor area, complete with a reflecting pool.

Patrons can have the best of both worlds, however, in the outdoor heated tent, which features hot-air circulation and transparent flaps that can be opened depending on the temperature.

And this isn’t your standard wedding tent — it withstands winds of up to 100 miles per hour.

“You still get the full effect of being outside,” says Christian Maniscalco (above), a 37-year-old from the Upper West Side who was enjoying a cocktail there. “I feel like it’s room temperature. I’m very comfortable.”

WINTER FUEL Guests can make use of chenille blankets while sipping on signature cocktails such as the feisty Excelsior, with silver tequila, lime juice, a dash of sugar and oranges spiced with chili ($15). The bar also offers classy munchies such as Wellfleet oysters (six for $20 or 12 for $36) and marinated olives ($7).

“When I opened, people said, ‘Why are you out on 11th Avenue?’ ” says Adam Block, the owner of the Press Lounge and its sister restaurant below, Print. “But when they saw the view from up here, they said, ‘Oh my God, I get it.’ ”